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An intraocular lens is disclosed, with an optic that changes shape in
response to a deforming force exerted by the zonules of the eye. A haptic
supports the optic around its equator and couples the optic to the
capsular bag of the eye. Certain haptic features improve the
accommodative performance of the haptic, such that compressive/tensile
forces may be more efficiently transferred from the haptic to optic.
Furthermore, certain aspects also provide enhanced bag-sizing capability
so that the IOL better fits within the capsular bag.

1. An intraocular lens for implantation into a capsular bag of an eye,
comprising: an adjustable central optic having an axial thickness through
the center thereof; and a haptic partly embedded within the adjustable
optic comprised of a central plate on one side of the optic midplane and
a plurality of legs radiating outward therefrom, each leg having
outermost convex curves to conform to the capsular bag, and a circular
array of teeth that project from the central plate generally in axial
directions and across the optic midplane, the teeth being embedded in the
optic, whereby the haptic is configured to transmit forces to alter at
least one of the shape and the thickness of the adjustable optic.

2. The intraocular lens of claim 1, wherein the central plate is stiffer
than the optic.

3. The intraocular lens of claim 1, wherein the central plate, legs, and
teeth are comprised of a material stiffer than the optic.

4. The intraocular lens of claim 1, wherein the teeth define a
rectilinear solid that gradually narrows from a base at the central plate
to a tip.

5. The intraocular lens of claim 3, wherein the teeth are angled
generally normal to the concave inner surface of the plate so that they
converge radially inward toward each other.

6. An intraocular lens for implantation into a capsular bag of an eye,
comprising: an adjustable central optic having an axial thickness through
the center thereof; and a haptic partly having a pair of curved
plate-like members that sandwich the optic therebetween, each curved
plate-like member having a concave face toward the optic and a convex
face away from the optic and a plurality of legs that extend outward
along generally the same curvature to contact the capsular bag, wherein
the legs of the curved plate-like members are interwoven so as to present
alternating axially-spaced legs to support the inside of the capsular
bag, whereby the haptic is configured to transmit forces to alter at
least one of the shape and the thickness of the adjustable optic.

7. The intraocular lens of claim 6, wherein the legs are wider than they
are thick.

8. The intraocular lens of claim 7, wherein the legs have a width that
increases radially outward.

9. The intraocular lens of claim 6, wherein the outer edges of the legs
are the widest and angled to closely match the curvature of a capsular
bag.

10. The intraocular lens of claim 6, wherein the plate-like members and
outer legs are comprised of materials stiffer than the optic.

11. An intraocular lens for implantation into a capsular bag of an eye,
comprising: an adjustable central optic having an axial thickness through
the center thereof; a haptic partly embedded within the adjustable optic
and having a plurality of legs radiating outward therefrom at angles to
the optic midplane to form two circumferential and axially-spaced arrays
of haptic leg ends to contact the capsular bag; and a circular ring in
the optic midplane sized to contact the capsular bag at its midplane,
whereby the haptic is configured to transmit forces to alter at least one
of the shape and the thickness of the adjustable optic.

12. A two-piece IOL system comprising: an adjustable central optic having
an axial thickness through the center thereof; a haptic partly embedded
within the adjustable optic and having a plurality of legs radiating
outward therefrom at angles to the optic midplane to form two
circumferential and axially-spaced arrays of haptic leg ends to contact
the capsular bag; and a circular ring in the optic midplane sized to
contact the capsular bag at its midplane, whereby the haptic is
configured to transmit forces to alter at least one of the shape and the
thickness of the adjustable optic; and a PCO ring capable of bag-sizing
and PCO prevention comprised of a capsular tension-type system around the
bag equator that limits the migration of lens epithelial cells from the
equator behind the optic.

13. The two-piece IOL system of claim 12, wherein the haptic legs are
offset angularly so as not to terminate along the equator.

14. The two-piece IOL system of claim 12, wherein the PCO ring has a
sharp edge.

15. An adjustable capsular ring for preventing posterior capsule
opacification, comprising: a flexible ring body having an opening,
wherein the ring body comprises a first end and a second end at the
opening, wherein the first end comprises multiple ratchet teeth and the
second end comprises a mating sleeve, wherein the multiple ratchet teeth
are capable of coupling with the mating sleeve such that ring can be
adjustably sized to fit a periphery of a capsular bag.

16. The adjustable capsular ring of claim 15, wherein each ratchet tooth
has a defined length such that a size of the ring can be determined based
on the location of the multiple ratchet teeth with respect to the mating
sleeve when the multiple ratchet teeth are coupled with the mating
sleeve.

17. The adjustable capsular ring of claim 16, wherein the ring body
further comprises a drug delivery system capable of eluting a drug.

19. An intraocular lens for implantation into a capsular bag of an eye,
comprising: an adjustable central optic having an axial thickness through
the center thereof; and a plurality of haptics having inner ends
connected to the adjustable optic and radiating outward therefrom; an
inflatable outer ring engaging outer ends of the haptics for adjusting
the radial position of the haptics, whereby the haptic is configured to
transmit forces to alter at least one of the shape and the thickness of
the adjustable optic.

20. The intraocular lens of claim 19, wherein at least one haptic has
multiple chambers within it.

21. The intraocular lens of claim 19, wherein the ring has multiple
chambers within it.

Description

[0001] The present application claims priority under 35 U.S.C .sctn.119(e)
to provisional application No. 60/220,887, filed on Jun. 26, 2009 under
the same title, which is incorporated herein by reference in its
entirety. Full Paris Convention priority is hereby expressly reserved.

FIELD OF THE INVENTION

[0002] The present invention relates to intraocular lenses, and more
particularly to accommodating intraocular lenses.

BACKGROUND OF THE INVENTION

[0003] A human eye can suffer diseases that impair a patient's vision. For
instance, a cataract may increase the opacity of the lens, causing
blindness. To restore the patient's vision, the diseased lens may be
surgically removed and replaced with an artificial lens, known as an
intraocular lens, or IOL. An IOL may also be used for presbyopic lens
exchange.

[0004] The simplest IOLs have a single focal length, or, equivalently, a
single power. Unlike the eye's natural lens, which can adjust its focal
length within a particular range in a process known as accommodation,
these single focal length IOLs cannot generally accommodate. As a result,
objects at a particular position away from the eye appear in focus, while
objects at an increasing distance away from that position appear
increasingly blurred.

[0005] An improvement over the single focal length IOLs is an
accommodating IOL, which can adjust its power within a particular range.
As a result, the patient can clearly focus on objects in a range of
distances away from the eye, rather than at a single distance. This
ability to accommodate is of tremendous benefit for the patient, and more
closely approximates the patient's natural vision than a single focal
length IOL.

[0006] When the eye focuses on a relatively distant object, the lens power
is at the low end of the accommodation range, which may be referred to as
the "far" power. When the eye focuses on a relatively close object, the
lens power is at the high end of the accommodation range, which may be
referred to as the "near" power. The accommodation range or add power is
defined as the near power minus the far power. In general, an
accommodation range of 2 to 4 diopters is considered sufficient for most
patients.

[0007] The human eye contains a structure known as the capsular bag, which
surrounds the natural lens. The capsular bag is transparent, and serves
to hold the lens. In the natural eye, accommodation is initiated in part
by the ciliary muscle and a series of zonular fibers, also known as
zonules. The zonules are located in a relatively thick band mostly around
the equator of the lens, and impart a largely radial force to the
capsular bag that can alter the shape and/or the location of the natural
lens and thereby change its effective power.

[0008] In a typical surgery in which the natural lens is removed from the
eye, the lens material is typically broken up and vacuumed out of the
eye, but the capsular bag is left intact.

[0009] The remaining capsular bag is extremely useful for an accommodating
intraocular lens, in that the eye's natural accommodation is initiated at
least in part by the zonules through the capsular bag. The capsular bag
may be used to house an accommodating IOL, which in turn can change shape
and/or shift in some manner to affect the power and/or the axial location
of the image.

[0010] The IOL has an optic, which refracts light that passes through it
and forms an image on the retina, and a haptic, which mechanically
couples the optic to the capsular bag or holds the IOL in contact with
the capsular bag. During accommodation, the zonules exert a force on the
capsular bag, which in turn exerts a force on the optic. The force may be
transmitted from the capsular bag directly to the optic, or from the
capsular bag through the haptic to the optic.

[0011] One challenge in implementing an accommodating optic is designing a
suitable haptic to couple the optic to the capsular bag. The haptic
should allow distortion of the optic in an efficient manner, so that a
relatively small ocular force from the ciliary muscle, zonules, and/or
capsular bag can produce a relatively large change in power and/or axial
location of the image. This reduces fatigue on the eye, which is highly
desirable.

[0012] Accordingly, there exists a need for an intraocular lens having a
haptic with increased efficiency in converting an ocular force to a
change in power and/or a change in axial location of the image.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Features and advantages of the present invention will become
appreciated as the same become better understood with reference to the
specification, claims, and appended drawings wherein:

[0014] FIG. 1 is a plan drawing of a human eye having an implanted
intraocular lens, in an accommodative or "near" state.

[0015] FIG. 2 is a plan drawing of the human eye of FIG. 1, in a
disaccommodative or "far" state.

[0016] FIG. 3 is a perspective view of a haptic for an intraocular lens
having a pair of axially spaced-apart and centered rings, and a plurality
of plate-like legs radiating outward therefrom;

[0017] FIG. 4 is a perspective view of a haptic for an intraocular lens
having a centered ring on one side of an optic midplane and a plurality
of legs extending outward therefrom in similar spirals;

[0018] FIG. 5A is a perspective view of a haptic for an intraocular lens
having a central vaulted portion including spokes each having a unitary
outer end and axially spaced apart bifurcated inner ends connected in two
axially spaced planes;

[0019] FIG. 5B is a perspective view of the haptic of FIG. 5A embedded
within an accommodative optic;

[0020] FIG. 6A is a perspective view of a haptic similar to FIG. 5A but
having a more conical central vaulted portion;

[0021] FIG. 6B is a perspective view of the haptic of FIG. 6A embedded
within an accommodative optic;

[0022] FIG. 7 is a perspective view of a haptic similar to FIG. 5A
embedded within an accommodative optic and having central throughholes in
the vaulted portion;

[0023] FIG. 8 is a perspective view of an intraocular lens with a haptic
having a central plate on one side of an optic midplane and a plurality
of legs radiating outward therefrom, and including a circular array of
teeth embedded in the optic;

[0024] FIG. 9 is a perspective view of an intraocular lens with a haptic
having curved plate-like members that sandwich an optic therebetween,
each curved plate-like member having a plurality of legs that extend
outward therefrom;

[0025] FIG. 10 is a perspective view of a haptic for an intraocular lens
having a centered ring and a plurality of legs radiating outward each
having an outer end capped with a flap-like appendage for fitting within
a capsular bag;

[0026] FIG. 11 is a perspective view of a haptic for an intraocular lens
having a centered ring and a plurality of legs radiating outward each leg
having an outer end that terminates in an annular tip;

[0027] FIGS. 12A and 12B are plan and detailed sectional views of a haptic
for an intraocular lens having a centered ring and a plurality of legs
radiating outward therefrom, each leg having a rounded cross-section;

[0028] FIG. 13A is a plan view of a system of a haptic for an intraocular
lens and a posterior capsule opacification (PCO) ring, the haptic having
a central ring from which a plurality of legs radiate outward at angles
to the optic midplane;

[0029] FIG. 13B is an elevational view of the haptic of FIG. 13A
positioned within a capsular bag shown in phantom;

[0030] FIGS. 14A and 14B are perspective and detailed views of an
adjustable PCO ring; and

[0031] FIGS. 15A and 15B illustrate an intraocular lens having a centered
ring, a plurality of haptics radiating outward therefrom, each haptic
having an outer end that terminates in an annular tip lying generally
parallel to the centered ring, and an inflatable outer ring.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] In a healthy human eye, the natural lens is housed in a structure
known as the capsular bag. The capsular bag is driven by a ciliary muscle
and zonular fibers (also known as zonules) in the eye, which can compress
and/or pull on the capsular bag to change its shape. The motions of the
capsular bag distort the natural lens in order to change its power and/or
the location of the lens, so that the eye can focus on objects at varying
distances away from the eye in a process known as accommodation.

[0033] For some people suffering from cataracts, the natural lens of the
eye becomes clouded or opaque. If left untreated, the vision of the eye
becomes degraded and blindness can occur in the eye. A standard treatment
is surgery, during which the natural lens is broken up, removed, and
replaced with a manufactured intraocular lens. Typically, the capsular
bag is left intact in the eye, so that it may house the implanted
intraocular lens.

[0034] Because the capsular bag is capable of motion, initiated by the
ciliary muscle and/or zonules, it is desirable that the implanted
intraocular lens change its power and/or location in the eye in a manner
similar to that of the natural lens. Such an accommodating lens may
produce improved vision over a lens with a fixed power and location that
does not accommodate.

[0035] A desirable optic for an accommodating IOL is one that distorts in
response to a squeezing or expanding radial force applied largely to the
equator of the optic (i.e., by pushing or pulling on or near the edge of
the optic, circumferentially around the optic axis). Under the influence
of a squeezing force, the optic bulges slightly in the axial direction,
producing more steeply curved anterior and/or posterior faces, and
producing an increase in the power of the optic Likewise, an expanding
radial force produces a decrease in the optic power by flattening the
optic. This change in power is accomplished in a manner similar to that
of the natural eye and is well adapted to accommodation. Furthermore,
this method of changing the lens power reduces any undesirable pressures
exerted on some of the structures in the eye.

[0036] FIG. 1 shows a human eye 10, after an accommodating intraocular
lens has been implanted. Light enters from the left of FIG. 1, and passes
through the cornea 11, the anterior chamber 12, the iris 13, and enters
the capsular bag 14. Prior to surgery, the natural lens occupies
essentially the entire interior of the capsular bag 14. After surgery,
the capsular bag 14 houses the intraocular lens, in addition to a fluid
that occupies the remaining volume and equalizes the pressure in the eye.
The intraocular lens is described in more detail below. After passing
through the intraocular lens, light exits the posterior wall 15 of the
capsular bag 14, passes through the posterior chamber 24, and strikes the
retina 16, which detects the light and converts it to a signal
transmitted through the optic nerve 17 to the brain.

[0037] A well-corrected eye forms an image at the retina 16. If the lens
has too much or too little power, the image shifts axially along the
optical axis away from the retina, toward or away from the lens. Note
that the power required to focus on a close or near object is more than
the power required to focus on a distant or far object. The difference
between the "near" and "far" powers is known typically as the add power
or as the range of accommodation. A normal range of accommodation is
about 2 to 4 diopters, which is considered sufficient for most patients,
but some have a range of 1 to 8 diopters.

[0038] The capsular bag is acted upon by the ciliary muscle 25 via the
zonules 18, which distort the capsular bag 14 by stretching it radially
in a relatively thick band about its equator. Experimentally, it is found
that the ciliary muscle 25 and/or the zonules 18 typically exert a total
ocular force of up to about 10 grams of force, which is distributed
generally uniformly around the equator of the capsular bag 14. Although
the range of ocular force may vary from patient to patient, it should be
noted that for each patient, the range of accommodation is limited by the
total ocular force that can be exert. Therefore, it is highly desirable
that the intraocular lens be configured to vary its power over the full
range of accommodation, in response to this limited range of ocular
forces. In other words, it is desirable to have a relatively large change
in power for a relatively small driving force.

[0039] Because the force exerted by the zonules, or ocular force, is
limited, in some cases it is desirable to use a fairly thin lens,
compared to the full thickness of the capsular bag. In general, a thin
lens may distort more easily than a very thick one, and may therefore
convert the ocular force more efficiently into a change in power. In
other words, for a relatively thin lens, a lower force is required to
cover the full range of accommodation. On the other hand, a soft, thicker
lens may be capable of changing shape from small capsular bag forces and
actually function better with fewer aberrations.

[0040] Note that the lens may be designed so that its relaxed state is the
"far" condition (sometimes referred to as "disaccommodative biased"), the
"near" condition ("accommodative biased"), or some condition in between
the two.

[0041] The intraocular lens itself generally has two components, an optic
21, which is made of a transparent, deformable and/or elastic material,
and a haptic 23, which holds the optic 21 in place and mechanically
transfers forces on the capsular bag 14 to the optic 21. The haptic 23
may have an engagement member with a central recess that is sized to
receive the peripheral edge of the optic 21. The haptic and optic may be
refractive index matched, though if at least some of the haptic is
embedded in or otherwise overlapping the optic the two materials must be
index matched.

[0042] When the eye 10 focuses on a relatively close object, as shown in
FIG. 1, the zonules 18 relax and compress the capsular bag 14 returns to
its natural shape in which it is relatively thick at its center and has
more steeply curved sides. As a result of this action, the power of the
lens increases (i.e., one or both of the radii of curvature can decrease,
and/or the lens can become thicker, and/or the lens may also move
axially), placing the image of the relatively close object at the retina
16. Note that if the lens could not accommodate, the image of the
relatively close object would be located behind the retina, and would
appear blurred.

[0043] FIG. 2 shows a portion of an eye 20 that is focused on a relatively
distant object. The cornea 11 and anterior chamber 12 are typically
unaffected by accommodation, and are substantially identical to the
corresponding elements in FIG. 1. To focus on the distant object, the
ciliary muscle 37 contracts and the zonules 26 retract and change the
shape of the capsular bag 25, which becomes thinner at its center and has
less steeply curved sides. This reduces the lens power by flattening
(i.e., lengthening radii of curvature and/or thinning) the lens, placing
the image of the relatively distant object at the retina (not shown).

[0044] For both the "near" case of FIG. 1 and the "far" case of FIG. 2,
the intraocular lens itself deforms and changes in response to the
ciliary muscles and/or to the distortion of the capsular bag. For the
"near" object, the haptic 23 compresses the optic 21 at its edge,
increasing the thickness of the optic 21 at its center and more steeply
curving its anterior face 19 and/or its posterior face 22. As a result,
the lens power increases. For the "far" object, the haptic 30 expands,
pulling on the optic 28 at its edge, and thereby decreasing the thickness
of the optic 28 at its center and less steeply curving (e.g., lengthening
one or both radius of curvature) its anterior face 27 and/or its
posterior face 29. As a result, the lens power decreases.

[0045] Note that the specific degrees of change in curvature of the
anterior and posterior faces depend on the nominal curvatures. Although
the optics 21 and 28 are drawn as bi-convex, they may also be
plano-convex, meniscus or other lens shapes. In all of these cases, the
optic is compressed or expanded by forces applied by the haptic to the
edge and/or faces of the optic. In addition, there may be some axial
movement of the optic. In some embodiments, the haptic is configured to
transfer the generally symmetric radial forces symmetrically to the optic
to deform the optic in a spherically symmetric way. However, in alternate
embodiments the haptic is configured non-uniformly (e.g., having
different material properties, thickness, dimensions, spacing, angles or
curvatures), to allow for non-uniform transfer of forces by the haptic to
the optic. For example, this could be used to combat astigmatism, coma or
other asymmetric aberrations of the eye/lens system. The optic may
optionally have one or more diffractive elements, one or more multifocal
elements, and/or one or more aspheric elements.

[0046] In many cases, it is desirable that during accommodation, the
distortion of the optic produces a change in optic thickness and/or a
change in the radius of curvature of the anterior and/or posterior
surfaces of the optic. Any other types of distortions to the surface,
such as "ripples" or "waves", may unacceptably degrade the optical
performance of the lens. These "ripples" or "waves" are described in more
detail below.

[0047] Because the optic is round, it may be difficult to envision any
undesirable surface ripples that may accompany a squeezing or expanding
of the optic about its equator. For this reason, it is instructive to
consider the geometry of a linear beam or rod, which can produce
analogous ripples along a single dimension. This 1-D geometry is much
simpler to visualize, and adequately describes the issue of undesirable
surface distortion.

[0048] Consider a linear beam or rod, which is being compressed by pushing
on its ends. While the intended effect of the compression may be to
shorten the beam and/or produce a slight bulge along the length of the
beam, an unintended effect may be to cause a small amount of "buckling"
along the length of the beam. Similarly, if the beam is stretched by
pulling on its ends, the intended effect of the stretching may be to
lengthen the beam and/or produce a slight thinning of the beam along its
length, but an unintended effect may be to cause a small amount of
"cracking" along the surface, similar in character to that of a desert
floor. Both the "buckling" and "cracking" may occur along the surface of
the beam, while the compression or expansion may be initiated at or near
the ends of the beam.

[0049] This analogy may be extended to the two-dimensional, essentially
circular geometry of the accommodating optic. To focus on relatively near
objects, as in FIG. 1, the haptic may squeeze the optic about its equator
and cause a radial compression of the optic. The intended effect of the
squeezing may be to increase the thickness of the optic and/or change the
curvature of the anterior and/or posterior surfaces of the optic.
However, an unintended effect may be to produce the two-dimensional,
circular equivalent of "buckling" on one or both of these surfaces.
Similarly, to focus on relatively distant objects, as in FIG. 2, the
haptic may stretch the optic about its equator and cause a radial
expansion of the optic. The intended effect of the expansion may be to
decrease the thickness of the optic and/or change the curvature of the
anterior and/or posterior surfaces of the optic. However, an unintended
effect may be to produce the twos dimensional, circular equivalent of
"cracking" on one or both of these surfaces. For the purposes of this
document, the circular equivalents of "buckling" and "cracking" may be
referred to as "ripples" or "waves". For known optics, these "ripples" or
"waves" may degrade the performance of the optic, which is highly
undesirable.

[0050] It is possible that the "ripples" or "waves" during accommodation
may be avoided if the optic has internal stress. For instance, if the
haptic applies a compression or expansion force to the optic, separate
and distinct from any compression or expansion forces applied by the
capsular bag of the eye, then the optic may have some internal stress,
which may reduce any "ripples" or "waves" that appear during
accommodation. The internal stress in the optic may be present throughout
the range of accommodation, or may alternatively pass through "zero" at
some point in the range of accommodation.

[0051] In some embodiments, the anterior and/or posterior surfaces may be
designed so that they attain particular profiles when the optic is
compressed about its equator, as occurs when the lens is implanted. For
instance, in some embodiments, it may be particularly desirable to have
spherical anterior and/or posterior surfaces; in these embodiments, the
anterior and/or posterior surface profiles may or may not deviate from
spherical when the optic is uncompressed about its equator. In other
words, for some embodiments, compressing the optic about its equator
causes the anterior and/or posterior surfaces to become more spherical in
profile. If there is asphericity in either surface in the uncompressed
state, it may be reduced when the optic is compressed.

[0052] For the purposes of this document, an intraocular lens and/or the
optic contained therein in which a haptic uses its internal stress to
affect the internal stress of the optic may be referred to as a
"pre-stressed" intraocular lens and/or a "pre-stressed" optic.

[0053] Many embodiments herein provide a haptic partly embedded within an
adjustable or accommodative central optic. The haptic transmits forces to
alter at least one of the shape and the thickness of the adjustable
optic. The materials of the haptic and optic may have similar compressive
or spring moduli, to encourage direct transfer of forces and reduce
uneven expansion/contraction and accompanying tension therebetween,
though the haptics are generally somewhat stiffer to be capable of
transmitting capsular forces. Additionally, similar material stiffness
may reduce the mismatch in shrinkage rates during molding or
post-processing, which mismatch may ultimately negatively impact lens
resolution. In one embodiment, the stiffnesses of the two materials are
within about 10% of each other and preferably within a range of about
20-100 kPa. Moreover, the two materials have similar refractive indices
to reduce any unwanted glare or reflection from light passing across
adjacent surfaces. A number of such embedded optics may be seen in U.S.
Patent Publications 2008-0161913 and 2008-0161914, the disclosures of
which are expressly incorporated herein.

[0054] A number of features described herein provide certain advantages to
intraocular lenses. For instance, various configurations improve the
accommodative performance of the haptic, such that compressive/tensile
forces may be more efficiently transferred from the haptic to optic.
Furthermore, certain aspects provide enhanced bag-sizing capability so
that the IOL better fits within the capsular bag. Some of these features
work together to provide both advantages, or may enhance the ability of
another feature to perform its function. Indeed, it should be understood
that any combination of individual haptic or IOL features described
herein may be formed even if not explicitly described or shown.

[0055] FIG. 3 is a perspective view of an accommodative haptic 50 for an
intraocular lens having a pair of axially spaced-apart rings 52 centered
around an optical axis OA, and a plurality of plate-like legs 54
radiating outward from each ring. The haptic 50 is desirably partly
embedded within an adjustable or accommodative central optic (not shown)
having an axial thickness through the center thereof. For instance, the
haptic 50 may be embedded in the optic such that rings 52 are within the
optic, but not all of the legs 54. The haptic 50 is configured to
transmit forces to alter at least one of the shape and the thickness of
the adjustable optic.

[0056] Desirably, the haptic 50 is symmetric across a midplane
perpendicular to the optical axis OA such that there are matching legs 54
connected to each ring. Preferably, each pair of matching legs 54 joins
together at their outer ends in a convex outer curve 56 that has an axial
dimension greater than the spacing between the rings 52. That is, in the
illustrated embodiment each two legs 54 and outer curve 56 are connected
to form an arrowhead shape, with short concave sections 58 therebetween.
As illustrated, there may be eight pairs of matching legs 54, though more
and as few as three are contemplated. The arrowhead-shaped outer ends of
the haptic legs 54 provides a capsular bag-filling outer profile to the
haptic 50 that better couples the bag forces to the central softer optic
to either expand or contract the optic axially. That is, forces exerted
on the outer ends of the haptic legs 54 are transmitted through the legs
to cause the spaced rings 52 to move apart or toward each other, thus
changing the shape of the surrounding soft optic. The change in the
surface shape of the optic changes the optic power thereof.
Alternatively, it is also possible to provide two rigid optics, one
attached to each of the two haptic rings 52, that move along the optical
axis OA to create power change.

[0057] FIG. 4 is a perspective view of a further haptic 60 for an
intraocular lens having a ring 62 centered around an optical axis OA and
on one side of an optic midplane perpendicular to the axis. A plurality
of legs 64 extend outward from the ring 62 in similar spirals and curve
axially. The legs 64 define outermost convex curves 66 and continue
radially inward on the opposite side of the optic midplane from the ring
62 to terminate in free ends 68. Indeed, the legs 64 are desirably
outwardly convex along their lengths to conform closely to a surrounding
capsular bag (not shown). The legs 64 preferably have a circumferential
width that exceeds their radial thickness (as measured in the midplane).
The resulting shape is analogous to a twisting pin-cushion.

[0058] As mentioned above, the haptic 60 is desirably partly embedded
within an adjustable or accommodative central optic (not shown) having an
axial thickness through the center thereof. For instance, the haptic 60
may be embedded in the optic such that ring 62 is within the optic, but
not all of the legs 64. In one embodiment, the ring 62 and the free ends
68 of the legs are embedded in the optic, but the outermost convex curves
66 are not. The haptic 60 transmits forces imparted by the surrounding
capsular bag to alter at least one of the shape and the thickness of the
adjustable optic. As can be appreciated, a compressive force radially
inward on the outermost convex curves 66 will tend to displace the ring
62 and the free ends 68 of the legs axially apart through the
straightening or "unwinding" of the spiral legs 64.

[0059] The haptic 60 of FIG. 4 may incorporate two optics axially spaced
along the optical axis OA such that at least one of the lenses rotates
relative or opposite to the other during accommodation. For instance, one
of the optics could be aspheric/asymmetrical such that the relative
rotation causes a power change in addition to any power change caused by
axial movement. In one embodiment, one optic spans and embeds the ring 62
and another optic spans and embeds the free ends 68. Although not shown
here, it is also possible to construct a haptic that is similar to this
one but symmetric about the horizontal plane so that two of the rings 62
are attached to the legs (without the free ends 68).

[0060] FIG. 5A illustrates a haptic 70 for an intraocular lens, while FIG.
5B shows the haptic embedded within an accommodative optic 72 (shown
translucent). The haptic 70 has a vaulted portion centered around an
optical axis OA including spokes 74 each having a unitary outer end 76
and axially spaced apart bifurcated inner ends 78 connected in two
axially spaced planes. In particular, the inner ends of the spokes 74
converge in two axially spaced-apart solid plates 80, denoted anterior
and posterior plates. The vaulted spokes 74 resembles a cage structure.
As mentioned above, the haptic 70 desirably is index matched with the
optic 72.

[0061] The spokes 74 preferably have a circumferential width that exceeds
their radial thickness (as measured in the midplane). More preferably,
the circumferential width of the spokes 74 gradually increases from their
connection with the central plates 80 outward to a maximum at their
connection to the unitary outer ends 76. The term "unitary" is meant
simply differentiate the bifurcated inner ends, and can be a variety of
shapes. In the illustrated embodiment, the outer ends 76 comprises
cylindrical rods or stubs that project radially outward from convex outer
portions of the spokes 74. Rounded or other more bag-conforming
structures may be provided on the outer ends of the cylindrical rods as
desired.

[0062] As with the earlier haptics, the haptic 70 transmits forces
imparted by the surrounding capsular bag to alter at least one of the
shape and the thickness of the adjustable optic. Namely, a compressive
force radially inward on the outer ends 76 will tend to spread the
bifurcated inner spoke ends apart, thus separating the anterior and
posterior plates 80 and accordingly axially thickening the optic 72.
Conversely, a relaxation of the capsular bag forces causes the spokes 74
to return outward, thus allowing the anterior and posterior plates 80 to
move together again. The radial length of the cylindrical rods 76 may be
varied to provide a number of different sizes of IOLs so as to better fit
various capsular bag sizes.

[0063] FIGS. 6A and 6B show a haptic 90 similar to that in FIG. 5A but
having a more conical central vaulted portion 92. It is also worth
mentioning that the haptics 70, 90 of FIGS. 5-6 include haptics having a
central solid portion across the optical axis OA. By choosing materials
of the haptic and optic that have similar refractive indices, the haptics
can exist even across the central optic zone. This configuration makes
possible a number of novel haptic shapes that may improve their
accommodative performance. That is, compressive/tensile forces may be
more efficiently transferred from the haptic to optic by providing this
central solid zone.

[0064] FIG. 7 is a perspective view of a haptic 100 also similar to that
in FIG. 5A embedded within an accommodative optic 102, yet having central
throughholes 104 in the vaulted portion.

[0065] FIG. 8 shows another haptic 110 having a solid central plate 112 on
one side of an optic midplane, and a plurality of legs 114 radiating
outward therefrom. A circular array of teeth 116 projects generally
axially (parallel to the optical axis) from one side of the central plate
112 and is embedded in a dome-like lens body 118. The central plate 112
is stiffer than the lens body 118, and the two are not necessarily index
matched.

[0066] Each leg 114 has an outermost convex curve 120 to conform to the
capsular bag. The curved outer ends of the haptic legs 114 provide a
capsular bag-filling outer profile to the haptic 110 that better fits the
interior of the bag. As with the other embodiments described herein, the
legs 114 transmit forces exerted on the outer ends 120 to cause a change
in surface shape or curvature of the lens body 118, thus changing the
optic power.

[0067] Each tooth 116 defines a rectilinear solid that gradually narrows
from a base at the central plate 112 to a tip 122. For instance, lateral
sides 124 of each tooth 116 may have a modified quadrilateral shape as
shown with an arcuate base at the central plate 112, two elongated linear
sides and a short linear side at the tip 122. The teeth are angled
generally normal to the concave inner surface of the plate 112 so that
they converge radially inward toward each other. Desirably, the central
plate 112, connected outer legs 114, and teeth 116 are all made of a
stiffer material than the softer dome-like lens body 118. During
accommodation, the teeth-like protrusions 116 of harder material inside
the softer material of the body 118 act to further transmit the forces
and alter the curvature of the lens body 118. The teeth 116 also act to
squeeze the softer lens body 118 and cause its surface curvature to
change, ideally in the opposite direction of the central plate 112, to
enhance power change.

[0068] FIG. 9 illustrates a further haptic 130 having opposed curved
plate-like members 132 that sandwich an optic 134 therebetween. Each
plate-like member 132 defines a concave face toward the optic 134 and a
convex face away from the optic, and a plurality of legs 136 that extend
outward from the perimeter of the optic along generally the same
curvature to contact the capsular bag (however, in some cases dissimilar
haptic leg curvatures may be desirable). The haptic legs 136 of the
opposed plate-like members 132 are interwoven so as to present
alternating axially-spaced legs to support the inside of the capsular
bag. Moreover, the legs 136 are desirably wider than they are thick, so
as to form curved plates, and have a width that increases radially
outward to resemble the legs of an Iron Cross. The outer edges 138 of the
legs 136 are the widest, and are desirably angled or contoured to more
closely match the curvature of the surrounding capsular bag. Other
conforming structure may be used, such as the flexible tips described
below.

[0069] The opposing plate-like members 132 including the outer legs 136
are typically stiffer materials than the softer optic 134. As before, the
haptic 130 transmits forces from the surrounding capsular bag to alter at
least one of the shape and the thickness of the adjustable optic 134. The
stresses transmitted through the outer legs 136 causes the plate-like
members 132 to bow or flatten, which then alters the thickness and/or
curvature of the softer central optic 134. As with most of the
configurations described herein, the different materials would typically
be refractive index matched to avoid unwanted optical effects. In some
configurations, some difference in refractive index is acceptable.

[0070] The haptic 150 of FIG. 10 includes a centered ring 152 and a
plurality of spoke-like legs 154 radiating outward therefrom. Each leg
154 has an outer end connected by a peripheral ring 156 and is capped
with a flap-like appendage 158 for fitting within a capsular bag. More
specifically, the flap-like appendage 158 extends generally axially in at
least one direction from the outer end of the respective leg 154. To
better conform to the capsular bag, each appendage 158 features a rounded
or convex outer surface 160 and an arcuate free edge 162 at its axial
extent.

[0071] As before, the haptic 150 is configured to transmit forces from the
capsular bag to alter at least one of the shape and the thickness of an
adjustable optic (not shown) within which the haptic is embedded. The
legs 154 are wedge-shaped with narrower inner ends at the centered ring
152 and wider outer ends at the peripheral ring 156. FIG. 10 also shows
optional cuts 164 in the inner ring 152 that assist in reducing the
resistance of movement of the ring to radial pressure from the bag. The
cuts 164 may also be wider spaces or slots.

[0072] The flap-like appendages 158 provide some flexibility or resilience
at the outer ends of the legs 154 so that the sizing of the intraocular
lens within the capsular bag is not as critical. That is, the capsular
bag is measured and an IOL chosen therefrom, but due to an incremental
size selection of haptics the spectrum of capsular bag sizes cannot be
precisely matched. However, the appendages 158 are cantilevered from the
legs 154 so that they bend somewhat if the bag is slightly smaller than
expected, thus providing a better structural engagement with the bag. The
haptic 150 is thus bag-size forgiving in that the floppy appendages 158
will give more or less depending on bag size. Further, the appendages 158
store some potential energy from bending to help assist in transmitting
bag forces into the central optic.

[0073] FIG. 11 shows another haptic 170 for an intraocular lens having a
centered ring 172 embedded in an optic 174 and a plurality of legs 176
radiating outward therefrom. Each leg 176 terminates in an outer end that
defines an annular tip 178. Each annular tip 178 is oriented generally
parallel to the centered ring 172 such that an oval-shaped central
opening 180 therein has an axis parallel to the optical axis OA. The
annular tips 178 are connected by a peripheral ring 182 with bowed out
sections between the legs 176.

[0074] The haptic legs 176 act as bumpers to allow some forgiveness in
bag-sizing whereby the annular tips 178 flex and absorb compressive
forces from the surrounding capsular bag. The bowed out sections of the
peripheral ring 182 also assist this flexing. This enhances the ability
of the haptic 170 to be properly sized within a range of bag sizes and
shapes. The peripheral ring 182 helps even out capsular bag forces to
adjacent legs 176. The tips 178 and bowed out sections of the peripheral
ring 182 give or squeeze a bit without compromising the accommodating
function of the IOL. Preferably there is some give which does not
significantly affect the magnitude of force from the bag being applied
into the central optic, or responsiveness to such capsular bag movement.

[0075] It should also be noted that all surfaces of the haptic 170 are
rounded to enhance conformity to the capsular bag and reduce irritation
that might occur from abrasion of sharp corners. The rounded surfaces
also help to reduce glare and reflections.

[0076] FIG. 12A is a plan view of a further haptic 190 for an intraocular
lens having a centered ring 192, a plurality of legs 194 radiating
outward therefrom, and a peripheral ring 196 connecting the outer ends of
the legs. As seen in the detail of FIG. 12B, each leg has a rounded
cross-section as with the haptic 170 above to reduce irritation with the
capsular bag, as well as optical glare and reflections. The peripheral
ring 196 has an undulating circumferential profile with inward bows
between the legs 194.

[0077] FIGS. 13A and 13B illustrate a system of a haptic 200 for an
intraocular lens and a surrounding posterior capsule opacification (PCO)
ring 202. The haptic 200 has a circular ring 204 in the optic midplane MP
from which a plurality of legs 206 radiate outward at angles to the optic
midplane to form two circumferential and axially-spaced arrays of haptic
leg ends 208 to contact a capsular bag 210, shown in phantom in FIG. 13B.
The haptic 200 is partly embedded within an adjustable optic 212 and
provides accommodation thereto as described. There are preferably at
least three haptic legs 206 angled to each side of the optic midplane MP
as shown, though more may be utilized (for instance, an Iron Cross
configuration as above). The legs 206 may be arranged symmetrically
across the optic midplane MP as shown or offset circumferentially. The
anterior and posterior side legs 206 are desirably equivalent in size and
shape, though different lengths and/or configurations are contemplated.
Likewise, the number of legs 206 on each side of the optic midplane MP
may not be equal.

[0078] The two-piece IOL system including the haptic 200 and PCO ring 202
may be implanted separately, typically the ring 202 first. The PCO ring
202 is formed as thin as possible and will not affect accommodation
provided by the haptic 200 to the optic 202. The system accomplishes
bag-sizing and PCO prevention by using the capsular tension-type ring 202
around the bag equator to limit the migration of lens epithelial cells
(i.e. PCO) from the equator behind the optic 212. The haptic legs 206 are
offset angularly so that they do not terminate along the equator and
interfere with the PCO ring. Some non-contiguous IOL designs may allow
PCO to creep in behind the optic, and therefore PCO is handled by
including the solid ring 202, preferably with a sharp edge, with the
haptic 200 shaped to work around that ring.

[0079] FIGS. 14A and 14B are perspective and detailed views of an
adjustable PCO ring 220 that may be used in place of the solid ring 202
of FIGS. 13A-13B. The ring 220 may include, for example, a zip-tie
configuration with a male end 222 having ratchet teeth that fits into a
female end 224 with a mating sleeve or pocket. The adjustable PCO ring
220 is used to both adjustably size itself against the capsular bag and
also provide a measurement of the bag size based on the amount that the
ring is contracted to fit. This can be calibrated to the number of teeth
clicks, for example. The zip-tie ring will really help address (IOL)
sizing in vivo and help ensure contact with the periphery of capsular bag
to translate forces from ciliary body/zonules for accommodation while
preventing PCO.

[0080] It should be noted that the rings 202, 220 in FIG. 13 or 14 could
also provide a drug-delivery type system, such as a drug-eluting
material, to further help prevent PCO.

[0081] According to another embodiment, an IOL may comprise one or more
haptics and/or one or more rings around an optic, wherein the haptics
and/or rings may be inflated. Inflation of the haptics and/or rings may
adjust the size of the haptics and/or rings to create a better fit within
the capsular bag and/or alter the stress on the optics. The haptics may
be of varying shapes, including but not limited to a pie or wedge shape
as illustrated in FIGS. 15A and 15B, a wheel/spoke configuration, or
other configuration described herein. The level of inflation of the
haptics and/or rings may be adjusted at the time of the initial
implantation of the IOL. The level of inflation may also be adjusted or
fine tuned during the life of the IOL, including but not limited to soon
after implantation, and/or months or years after implantation. The fine
tuning or adjustment may be made to enhance the patient's visual outcome
over time. The haptics may be filled with anything known in the art
including, but not limited to, saline, air, and/or silicone. The optic,
haptics, and/or rings may have varying flexibility/stiffness depending
upon the needs of the patient, the characteristics of the patient's eye,
and/or the desired characteristics of the IOL. The haptics and/or rings
may also have multiple chambers within each haptic and/or ring that are
inflatable. Each chamber may be filled to different levels, thereby
customizing the shape of the IOL to the capsular bag and/or varying the
stresses on the optic to allow for non-uniform transfer of forces by the
haptic to the optic.

[0082] FIGS. 15A and 15B illustrate an embodiment of the present
invention. In FIG. 15A, multiple wedge shaped haptics are shown radiating
outward around a center optic. The haptics are connected to an inner ring
of the optic and an inflatable outer ring. Inflation of the outer ring
adjusts the overall size of the IOL, as seen in FIG. 15B, enabling better
fit of the IOL within the capsular bag. The inflation may also place
stress on the optics as the haptics are connected to the inner ring of
the optic and the inflatable outer ring. Such stress may change the
thickness and/or shape of the optic. It is also envisioned that an IOL of
the present invention comprises an inflatable inner ring and an
inflatable outer ring, both of which are adjustable. The inner ring may
be connected to the optic.

[0083] While the invention has been described in its preferred
embodiments, it is to be understood that the words which have been used
are words of description and not of limitation. Therefore, changes may be
made within the appended claims without departing from the true scope of
the invention.